Telephone hand set



Dec. 26, 1922. 1,439,729

G. DEAKIN. TELEPH HAND SET, FILED a P 7. 1922. 2 SHEETS-SHEET l fivvenfor: Gera/d Beak/n.

distance equal to the distance between the studs 18. Thewidth of the slots is equal to the width of the smaller cross section of the studs 18 at the shoulders 23. i The upperends 26 of the slots are enlarged and surrounded as shown so as to permit the passage of the studs 18 th'erethrough. The

sor'ings 12 attached to the front plate are of such a length and are so located as to ex tend below and opposite to theslots 25. ,Zi;

hole 2? is provided in the lower port-ion of the front plate 2 through which passes the ,cord 22% containing the usual conductors for connecting upvelectrically the elements'of the instrument.

In F 1g. 3 the electrical connections of'the instrument arev diagrammatically illustrated.

,rhe receiver 5 and transmitter 6 are connected in series through the springs 11 and 12, which are normally closed when the calling dial is not attached. The dial is connected to the pins 21, While the leads 29 and may terminate in suitable clips for making electrical connection with a desired line.

To attach the calling dial to the instrument, the studs 18 are pushed through the rounded ends 26 of the slots 25 and the casing l7 containing the (lial is then pushed down until the ends of the slots 25 are cugaged bythe studs 18 when the rounded end 9 of the spring 8 passes through the slot 2%- in the casin 17. The shoulders 23 upon the studslS engage the front plate 2 so that this plate tits between the shoulders and the casing 17 as clearly pins 21 engage the springs 12 and push the latter out of engagement with the springs 11 so that the calling dial is now connected in series with the receiver and transmitter.

mountedon the stem, and means for keep- I shown in 5 The.

ing said circuit closed at all times and for keeping it closed through the dial when, and only when, the latter is attached to the stem.

3. in combination, a telephone hand set comprising a stem, slots therein, a calling dial, studs in the dial to engage said slots and to hold the dial upon the hand set, said studs forming the electric terminals of the dial, and contacts in proximity to the studs for engaging the studs. I a

4. In combination, a telephone hand set comprising a stem member, a calling dial,a case'for the dial, an opening therein, a of slots in said stem,'a pair or studs on said 7 case having shoulders thereon to engage said slots and to hold the dial upon the hand set, said studs forming the electric terminals of the dial, a pair oi contacts in proximity to the slots for engagement to studs, and Ya spring member fixed to the stem of the hand set and passing through an opening therein to engage the opening in said case when the dial is attached to the stem so as to lock the dial in place;

In combination, a telephone hand set comprising a stem, an electric circuit therein,

a callingdial, a casing therefor, a pair of slots in said stein, a pair of studs on the dial casing to engage said slots and to hold the dial upon the hand set, thestuds forming the electric terminals for the dial, a pair or" contact springs adapted normally to close the electriccircuit and upon operation of said studs to insert the dial in said circuit when it is attached to the hand set.

6. In combination, a telephone hand set comprising a stem, an electric circuit there'- in,'a calling dial, a pair of slots in said stein, a pair ofstuds on the dial to engage said siots and to hold the dial upon the stem, :1 pair of contact pins passing through said studs, a pair of contact springs in the hand set to engage the pins and to electric; connect the dial and the hand set when ic dial is in engagement therewith, and to automatically close said circuit when the dial is not in engagement therewith.

In witness whereof, I hereunto subscribe my name this 18th day of August, A;

GERALD DEAKIN. 

